(somE) mEthoDs (to prEvEnt) soil Erosion(侵蚀) ) (ArE) plowing pArAllEl with thE slopEs oF hills, (to plAnt) trEEs on unproDuCtivE lAnD, AnD rotAting Crops.
A. somE
B. to prEvEnt
C. ArE
D. to plAnt